A regular full sized, self contained, motor home is built to have adequate head room and standing space for both comfort and convenience. But, as a consequence, such motor homes are also built to such a height, above ground level, that they can not be parked or housed in the ordinary garage which was built for the family car.
Although efforts have been made to provide some type of pop-up top for the smaller sized vans and to outfit them for self-contained motor home use, none of these have been too successful.
While some success has been achieved in the use of a dropped floor in the smaller vans, to provide the desired standing space and head room in a vehicle having a relatively low profile, the extent of such use has been severly limited in having to be on just one side of the drive shaft which extends under the vehicle. And also because of the structural problem due to frame cross-members and the like which can not be interrupted.
Because of such limitations, most dropped floors in vans have been just at or near the access door, where they can extend to the side of the vehicle. Otherwise, they appear rather deep and narrow when made to extend lengthwise and in front of the storage cabinets and appliances. And, they are usually awkward to use or turn around in.
As a consequence, the dropped floor has appeared to have its limitations except for front wheel drive vehicles when and as developed for van use and motor home adaptation.